Pak. J. Bot., 43(4): 2023-2028, 2011.
RELATIONSHIP BETWEEN MORPHOLOGICAL CHARACTERS OF DIFFERENT AUBERGINE CULTIVARS AND FRUIT INFESTATION BY LEUCINODES ORBONALIS GUENEE HUMAYUN JAVED1*, ATA-UL-MOHSIN1, MUHAMMAD ASLAM1, MUHAMMAD NAEEM1, MUHAMMAD AMJAD2 AND TARIQ MAHMOOD3 1
Department of Entomology, PMAS- Arid Agriculture University Rawalpindi, Pakistan. 2 Oil Seed Programme, NARC, Islamabad, Pakistan. 3 Department of Environmental Sciences, PMAS-Arid Agriculture University Rawalpindi, Pakistan. * Corresponding Author:
[email protected] Abstract Response of different aubergine cultivars against brinjal shoot and fruit borer (Leucinodes orbonalis Guenee.) was evaluated at National Agriculture Research Centre, Islamabad during 2007-08 and 2008-09. The results reflected different levels of infestation in all cultivars by the pest. Cultivar Naeelam showed maximum fruit infestation (58.60 and 48.09%) followed by Black long (47.93 and 33.31%), while minimum was observed in Nirala with 24.75 and 21.57% fruit infestation during 2007-08 and 2008-09, respectively. Similarly, shoot infestation was found maximum in Naeelam (43.15 and 33.75%) followed by Kanha-091 (37.72 and 28.73 %) and Nirala was found to be least attacked by the pest showing 19.27 and 15.81% shoot infestation during 2007-08 and 2008-09, respectively. The correlation of different morphological plant characters with fruit infestation indicated very strong and negative correlation between fruit infestation and leaf trichomes, stem thickness and stem hair density. A negatively significant correlation was found between fruit infestation and plant height (r = – 0.716), crown hair density (r = – 0.672) while the correlations of leaf hair density (r = – 0.623), and leaf area (r = – 0.613), was also significant and negative but not so strong. There was positive correlation with fruit yield (q/acre) and positive and non significant correlation with number of primary branches/plant with r-value 0.661and 0.319, respectively.
Introduction Brinjal, also known as eggplant or aubergine belonging to the family “Solanaceae”, is one of the common and popular vegetables grown throughout the world. The family contains more than 2450 species distributed in 95 genera (Mabberley, 2008). There are 3 main varieties of bringal generally cultivated in Pakistan. The crop is extensively damaged by insect pests and diseases apart from other constraints. In Pakistan, aubergine is mainly cultivated on small scale, but is a potential source of income for the farmers. Several factors are responsible for the low productivity of aubergine in Pakistan. These include biotic factors as insect pests and pathogens. The losses caused by brinjal pests vary from season to season depending upon environmental factors (Gangwar & Sachen, 1981). The most extensive pest of this vegetable is brinjal shoot and fruit borer (Lucinodes orbonalis Guenee) which reduces the yield and inflicts colossal loss in production. Due to its high reproductive potential, rapid turnover of generations and intensive cultivation of aubergine in both wet and dry seasons, the pest poses a serious threat. The newly hatched larvae bore into the petioles, midribs of large leaves and young tender shoots. The entry place of the larvae is closed by their excreta and feeding is internal (Butani & Jotwani, 1984). A single larva of L. orbonalis is enough to damage 4-6 healthy fruits (Anonymous, 2010).Due to larval activity, translocation mechanism of nutrients in shoot is affected causing dropping and withering of shoots (Alam & Sana, 1962). In later stages the larvae bore into young fruits through the soft calyx tissue leaving no sign of infestation (Butani & Jotwani, 1984). Secondary infestation by certain bacteria may cause further loss to the quality of the fruit (Islam & Karim, 1994) through fruit rottening which renders them unfit for marketing and human consumption. This pest
causes 31-86% fruit damage in Bangladesh (Alam et al., 2003) which may reach up to 90% (Rahman, 1997) and 50-70% in Pakistan (Saeed & Khan, 1997). This pest is serious problem for the aubergine growers and may reduce the crop yield up to 60-70-70 % (Shailendra and Pras Nath, 2010). For the management of this pest organic insecticides are being used, but the use synthetic insecticides is very hazardous to human health as the crop is a staple food and consumed in its original form. Pesticide use is also a threat to natural enemies and non target insects. Extensive and indiscriminate use of pesticides is responsible for the development of resistance in the pests; persistent effects of chemicals, constantly polluting our environment and through bio-magnification have become the part of human food chain. Thus the unchecked use of chemicals is hazardous not only to humans but to other flora and fauna. The most important and effective way to manage an insect pest is the use of resistant cultivars. Host plant resistance strategy serves as an excellent component when integrated with other approaches as it has several advantages over other measures. It is highly compatible with pesticides and biological control agents. Besides its effectiveness, selectivity against the pest and relatively long stability makes this tactic a cornerstone of IPM systems. The resistant varieties can easily be adopted in crop production schemes and reduce the cost of produce. Therefore, objectives of this study are to determine the response of different morphological characters of aubergine cultivars against brinjal fruit and shoot borer. Materials and Methods The research work was conducted at the National Agricultural Research Centre, Islamabad. Aubergine germplasm for the preliminary screening for resistance against L. orbonalis, was taken from National Agricultural
HUMAYUN JAVED ET AL.,
2024 Research Centre, Islamabad and different seed stores of Rawalpindi, Taxila and. Gujranwala. The cultivars used were Violet Prince 101, Ep-273, Kanha-091, Anmol, Karishma, Nirala, Brinjal long, Long purple black, Naeelam, Brinjal pusa Karanti, Purple long, Chinese brinjal and black long. The experiment was conducted in Randomized Complete Block Design using 13 brinjal cultivars with 4 replications during 2007-08. Plots measuring 11.5 × 7.0 m were prepared for sowing. All the recommended agronomic practices (weeding, hoeing, application of farm yard manure etc.) were followed in these plots. Seedlings of each of 13 varieties were raised in green house of vegetable section of NARC, Islamabad. Four weeks after germination, seedlings of each variety were transplanted to experimental plots. A plant to plant distance of 60 cm and row to row distance of 75 cm was maintained while transplanting the seedling. The larval population of brinjal shoot and fruit borer was recorded from 10 randomly selected aubergine plants from each experimental unit; one leaf each from top, middle and lower portion of each selected plant at weekly intervals. The average larval population per leaf was calculated lately. The infestation of brinjal shoot and fruit borer larvae on shoots and fruits of different cultivars of aubergine was recorded by counting healthy and damaged shoots and fruits from 10 randomly selected plants from each experimental unit. The data were taken regularly at weekly intervals. Then percentage values for both shoot and fruit damage were calculated. The data regarding population and infestation percentage of brinjal shoot and fruit borer (L. orbonalis) on aubergine cultivars recorded during preliminary screening trial was subjected to statistical analysis and the means were compared by Duncan’s Multiple Range Test at 5% probability. Out of 13 aubergine cultivars, two cultivars viz., Nirala, Anmol were found relatively resistant 3 cultivars viz., Karishma, Kanha-091, EP-273 intermediate resistant and 2 susceptible cultivars i.e., Naeelam, Black long. Their morphological characteristics were studied based on fruit infestation and sown again on the same experimental area next year (2008) for the final screening. Morphological characters of aubergine plants: Morphological variations in 7 aubergine cultivars were studied to investigate their role against fruit infestation of L. orbonalis from (Table 1). Yield (kg/plot) of different aubergine cultivars were taken starting from first picking up to final picking and converted into q/acre. Then the yield of various aubergine cultivars was correlated with the extent of infestation on fruits to each cultivar. Statistical analysis: The data regarding different parameters were subjected to analysis of variance using M Stat Software to evaluate the difference between morphological characters of different cultivars and their means comparison was conducted using LSD-Test at 5% level of probability. The data were then processed for simple correlation and Multiple Linear Regression analysis to determine their impact on fruit infestation caused by brinjal shoot and fruit borer (L. orbonalis).
Results and Discussion Larval population/ Leaf: Means comparison of the data pertaining to number of larval population per leaf showed significantly different response of cultivars during 2007. The cultivar Naeelam showed maximum larval population per leaf (1.14), while Nirala was proved comparatively less preferred by larvae of the brinjal shoot and fruit borer (Table-2). During final screening trial maximum larval population of L. orbonalis was found in both Naeelam (1.03) and Black long (0.98) and were found statistically similar (Table 3). Nirala was comparatively less preferred with 0.15 larvae per leaf followed by Anmol (0.32 larvae per leaf). Shoot infestation (%): The comparison of means of the data regarding percent shoot infestation of L. orbonalis during preliminary screening trial revealed significantly high difference among cultivars at 5% probability (Table 2). Maximum shoot infestation was observed on the cultivar Naeelam (43.15%) followed by Kanha-091 with 37.72% shoot infestation. Cultivar Nirala had minimum (19.27%) shoot infestation. During second year of the study (2008), minimum shoot infestation was observed in Nirala (15.81%) which was statistically similar with EP273 having 16.55 % shoot infestation. Whereas, Naeelam was the most preferred cultivar for brinjal shoot and fruit borer with mean value of 33.75 % followed by Kanha-091 with 28.73% shoot infestation. Jat et al., (2003) reported 3.28 to12.71% variations in shoot infestation in 10 different varieties of aubergine. Lowest shoot infestation (3.28%) was observed in Arka Kasumkara. Similarly, Senapati (2003) also recorded very low shoot infestation (4 to 11.1%) during screening of twelve aubergine cultivars against L. orbonalis. The very low shoot infestations in these studies may be attributed to the different climatic conditions and varieties in their experiments. Fruit infestation (%): During first year of studies, cultivar Naeelam showed maximum fruit infestation i.e., 58.60 %, followed by Black long (47.93 %). The minimum fruit infestation (24.75 %) was recorded on Nirala which differed significantly from all other cultivars (Table-2). During final screening, it was observed that Naeelam showed maximum fruit infestation i.e. 48.09 percent followed by Black long (33.31%). The fruit infestation was recorded to be 30.03, 29.76, 28.84 and 28.18 % on the Anmol, Kanha (091), Karishma and EP273 cultivars, respectively and did not show significant difference with each other. The minimum fruit infestation i.e., 21.57% was observed on Nirala. Comparable range of fruit infestation was 20.23 to 45.61% reported by Jat et al., (2003), though they used different set of varieties/cultivars in their experiment. Similarly, Krishna et al., (2001) found 43% fruit infestation in Ramy round purple of India which was comparatively the most susceptible while minimum shoot infestation was reported in SM-02. Kumar & Shukla (2002) found 33 to 53% damage of fruits in 12 different cultivars of aubergine. Similarly, Ashoke & Abhishek (2002) while evaluating 12 aubergine cultivars in field conditions reported 33.6553.02% fruit infestation of L. orbonalis larvae. Conversely, Chaudhary & Sharma (2000) found very low
RELATIONSHIP BETWEEN PHYSICO-MORPHIC CHARACTERS OF DIFFERENT BRINJAL CULTIVARS
attack of brinjal shoot and fruit borer (2.88-5.64%) during screening of nine genotypes of aubergine. Gangopadhay et al., (1996) found infestation of L. orbonalis in every variety under investigation; moreover exotic varieties were more infested as compared to the local ones. Sharma
2025
et al., (1998) evaluated the response of 8 cultivars of aubergine for tolerance against L. orbonalis, but their results could not be compared with present studies due to difference in genotypes used in their experiments.
Table1. Morphological characteristics of aubergine cultivars and the methodology used for their study. Morphological characteristics Methodology Hair density on fruit crown /cm² The fruits were randomly collected each from ten different plants (from each of the test entry). From crown of each fruit three pieces of one cm2 were cut and examined under Microscope to count their hair density/cm2 and average was worked out. Hair density of leaf lamina /cm² Three pieces of leaf lamina each of one cm2 area were cut from top, middle, and lower portion leaves of the randomly selected ten plants from each experimental unit. Number of hair/cm2 from each piece was counted under Microscope and their average was worked out. Hair density on shoots /cm The number of hairs /cm of the shoot were counted by taking a piece of one cm from ten randomly selected plants from each experimental unit at an interval of 40, 90, and 140 days after transplantation. Plant height /cm Height of ten randomly selected plants from each plot was measured with the help of meter rod at an interval of 40, 90 and 140 days after transplanting of brinjal plants and finally their averages were computed. Stem girth/ mm The stem girth was recorded from randomly selected ten plants from each experimental unit with the help of measuring tape at an interval of 40, 90 and 140 days after transplantation. Leaf area/cm2 Three leaves each from upper, middle and lower portion of each test entry were taken and brought in the laboratory. Leaf area (cm2) was measured with the help of leaf area meter at an interval of 40, 90, and 140 days after transplanting. Number of primary branches/ Total primary branches arising from the basal node were counted from randomly plant selected ten plants in each plot and their average was worked out. Trichomes/leaf Total number of trichomes from upper, middle and lower leaves of different plants from each plot, were examined to count the average number of trichomes present on its upper side. Table 2. A comparison of mean values for the data regarding larval population and fruit (%) infestation of Leucinodes orbonalis (Guenee) in different aubergine cultivars during 2007.
Cultivars Naeelam Brinjal long Kanha-091 Long purple black Purple long Brinjal pusa kranti Ep-273 Chinese brinjal Anmol Black long Karishma Violet prince 101 Nirala LSD Analysis of variance
Larval population (Leaf-1) 1.14 a 0.42 d 0.56 bc 0.53 c 0.60 b 0.54 c 0.35 ef 0.55 c 0.44 d 0.38 e 0.34 f 0.34 f 0.29 g 0.345 F12, 675 =1398.80 p
